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About SWinG

Attention: MDL's SREF Winter Guidance (SWinG) is a prototype! Data on these pages may not always be current.

SREF Winter Guidance (SWinG) uses output from the Short Range Ensemble Forecast system (SREF) to produce reliable and accurate probability distributions of weather elements at a set of stations. Unlike traditional Model Output Statistics (MOS), SWinG uses statistical postprocessing methods that work with short samples. The most important of these techniques is a modified form of Bayesian Model Averaging (BMA).

Note: The SWinG project is actively using the NWS V-lab (NWS Portal), where users can leave feedback and view additional documentation and case studies

View SWinG Forecast Images and Text

SWinG images are meteograms or "plume diagrams". They show the time evolution of the probability distributions of a number of weather elements for a single station. The black line shows the median of the distribution, and shaded areas show the 10th, 30th, 70th, and 90th percentiles.

SWinG text forecasts are whitespace-delimited files that contain forecasts for a single weather element. Each line represents a forecast probability distribution for one station at one time projection. Here is an explanation of the columns:

Column

Heading

Explanation

1

VALIDTIME

The forecast date and time as yyymmddhh

2

STN

Station Identifier (stations with # in their identifiers are substitutions.
See our Station List

3-13

CDF05-CDF95

The labeled percentile of the forecast distribution. E.g., if CDF30=1.5 degrees Celsius, then there is a 30 percent chance the temperature will be 1.5 degrees Celcius or less.